2 * arch/alpha/boot/bootp.c
4 * Copyright (C) 1997 Jay Estabrook
6 * This file is used for creating a bootp file for the Linux/AXP kernel
8 * based significantly on the arch/alpha/boot/main.c of Linus Torvalds
10 #include <linux/kernel.h>
11 #include <linux/slab.h>
12 #include <linux/string.h>
13 #include <generated/utsrelease.h>
16 #include <asm/system.h>
17 #include <asm/console.h>
18 #include <asm/hwrpb.h>
19 #include <asm/pgtable.h>
26 extern unsigned long switch_to_osf_pal(unsigned long nr,
27 struct pcb_struct * pcb_va, struct pcb_struct * pcb_pa,
30 extern void move_stack(unsigned long new_stack);
32 struct hwrpb_struct *hwrpb = INIT_HWRPB;
33 static struct pcb_struct pcb_va[1];
36 * Find a physical address of a virtual object..
38 * This is easy using the virtual page table address.
42 find_pa(unsigned long *vptb, void *ptr)
44 unsigned long address = (unsigned long) ptr;
47 result = vptb[address >> 13];
50 result |= address & 0x1fff;
51 return (void *) result;
55 * This function moves into OSF/1 pal-code, and has a temporary
56 * PCB for that. The kernel proper should replace this PCB with
57 * the real one as soon as possible.
59 * The page table muckery in here depends on the fact that the boot
60 * code has the L1 page table identity-map itself in the second PTE
61 * in the L1 page table. Thus the L1-page is virtually addressable
62 * itself (through three levels) at virtual address 0x200802000.
65 #define VPTB ((unsigned long *) 0x200000000)
66 #define L1 ((unsigned long *) 0x200802000)
72 struct percpu_struct * percpu;
73 struct pcb_struct * pcb_pa;
75 /* Create the dummy PCB. */
78 pcb_va->ptbr = L1[1] >> 32;
85 pcb_pa = find_pa(VPTB, pcb_va);
89 * a1 = return address, but we give the asm the vaddr of the PCB
90 * a2 = physical addr of PCB
91 * a3 = new virtual page table pointer
92 * a4 = KSP (but the asm sets it)
94 srm_printk("Switching to OSF PAL-code .. ");
96 i = switch_to_osf_pal(2, pcb_va, pcb_pa, VPTB);
98 srm_printk("failed, code %ld\n", i);
102 percpu = (struct percpu_struct *)
103 (INIT_HWRPB->processor_offset + (unsigned long) INIT_HWRPB);
104 rev = percpu->pal_revision = percpu->palcode_avail[2];
106 srm_printk("Ok (rev %lx)\n", rev);
108 tbia(); /* do it directly in case we are SMP */
112 load(unsigned long dst, unsigned long src, unsigned long count)
114 memcpy((void *)dst, (void *)src, count);
123 __asm__ __volatile__(
126 : /* no outputs: it doesn't even return */
131 #define KERNEL_ORIGIN \
132 ((((unsigned long)&_end) + 511) & ~511)
138 * Note that this crufty stuff with static and envval
139 * and envbuf is because:
141 * 1. Frequently, the stack is short, and we don't want to overrun;
142 * 2. Frequently the stack is where we are going to copy the kernel to;
143 * 3. A certain SRM console required the GET_ENV output to stack.
144 * ??? A comment in the aboot sources indicates that the GET_ENV
145 * destination must be quadword aligned. Might this explain the
146 * behaviour, rather than requiring output to the stack, which
147 * seems rather far-fetched.
150 static char envval[256] __attribute__((aligned(8)));
151 static unsigned long initrd_start;
153 srm_printk("Linux/AXP bootp loader for Linux " UTS_RELEASE "\n");
154 if (INIT_HWRPB->pagesize != 8192) {
155 srm_printk("Expected 8kB pages, got %ldkB\n",
156 INIT_HWRPB->pagesize >> 10);
159 if (INIT_HWRPB->vptb != (unsigned long) VPTB) {
160 srm_printk("Expected vptb at %p, got %p\n",
161 VPTB, (void *)INIT_HWRPB->vptb);
166 /* The initrd must be page-aligned. See below for the
167 cause of the magic number 5. */
168 initrd_start = ((START_ADDR + 5*KERNEL_SIZE + PAGE_SIZE) |
170 #ifdef INITRD_IMAGE_SIZE
171 srm_printk("Initrd positioned at %#lx\n", initrd_start);
175 * Move the stack to a safe place to ensure it won't be
176 * overwritten by kernel image.
178 move_stack(initrd_start - PAGE_SIZE);
180 nbytes = callback_getenv(ENV_BOOTED_OSFLAGS, envval, sizeof(envval));
181 if (nbytes < 0 || nbytes >= sizeof(envval)) {
184 envval[nbytes] = '\0';
185 srm_printk("Loading the kernel...'%s'\n", envval);
187 /* NOTE: *no* callbacks or printouts from here on out!!! */
189 /* This is a hack, as some consoles seem to get virtual 20000000 (ie
190 * where the SRM console puts the kernel bootp image) memory
191 * overlapping physical memory where the kernel wants to be put,
192 * which causes real problems when attempting to copy the former to
195 * So, we first move the kernel virtual-to-physical way above where
196 * we physically want the kernel to end up, then copy it from there
197 * to its final resting place... ;-}
201 #ifdef INITRD_IMAGE_SIZE
202 load(initrd_start, KERNEL_ORIGIN+KERNEL_SIZE, INITRD_IMAGE_SIZE);
204 load(START_ADDR+(4*KERNEL_SIZE), KERNEL_ORIGIN, KERNEL_SIZE);
205 load(START_ADDR, START_ADDR+(4*KERNEL_SIZE), KERNEL_SIZE);
207 memset((char*)ZERO_PGE, 0, PAGE_SIZE);
208 strcpy((char*)ZERO_PGE, envval);
209 #ifdef INITRD_IMAGE_SIZE
210 ((long *)(ZERO_PGE+256))[0] = initrd_start;
211 ((long *)(ZERO_PGE+256))[1] = INITRD_IMAGE_SIZE;